Mitsubishi Montero (2004+). Manual — part 128

The Multiport Fuel Injection System consists of sensors
which detect the engine conditions, the POWERTRAIN
CONTROL MODULE (PCM) which controls the system
based on signals from these sensors, and actuators which
operate under the control of the PCM.
The PCM carries out activities such as fuel injection con-
trol, idle air control, and ignition timing control.
In addition, the PCM is equipped with several diagnostic
test modes which simplify troubleshooting when a problem
develops.

FUEL INJECTION CONTROL
The injector drive times and injector timing are controlled
so that the optimum air/fuel mixture is supplied to the
engine to correspond to the continually-changing engine
operation conditions.
A single injector is mounted at the intake port of each cyl-
inder. Fuel is sent under pressure from the fuel tank to the
fuel injectors by the fuel pump, with the pressure being
regulated by the fuel pressure regulator. The regulated
fuel is distributed to each of the injectors.
Fuel injection is normally carried out once for each cylin-
der for every two rotations of the crankshaft. The firing
order is 1-2-3-4-5-6. Each cylinder has a dedicated fuel
injector. This is called multiport.
The PCM provides a richer air/fuel mixture by carrying out
"open-loop" control when the engine is cold or operating
under high load conditions in order to maintain engine per-
formance. In addition, when the engine is under normal
operating temperature after warming-up, the PCM controls
the air/fuel mixture by using the heated oxygen sensor sig-
nal to carry out "closed-loop" control. The closed-loop con-
trol achieves the theoretical air/fuel mixture ratio where
the catalytic converter can obtains the maximum cleaning
performance.

THROTTLE VALVE OPENING CONTROL
This system electrically controls the opening of the throttle
valve. The PCM detects the amount of travel of the accel-
erator pedal via the accelerator pedal position sensor, and
controls the actuation of the throttle actuator control motor,
which is mounted on the throttle body, in order to attain the
target throttle valve opening that has been predetermined
in accordance with driving conditions.

IDLE AIR CONTROL
The idle speed is kept at the optimum speed by controlling
the amount of air that passes through the throttle valve in
accordance with changes in idling conditions and engine
load during idling.

The PCM drives the throttle actuator control motor to keep
the engine running at the pre-set idle target speed in
accordance with the engine coolant temperature and A/C
and other electrical load. In addition, when the air condi-
tioning switch is turned off and on while the engine is
idling, the throttle actuator control motor adjusts the throt-
tle valve passes through air amount according to the
engine load conditions to avoid fluctuations in the engine
speed.

IGNITION TIMING CONTROL
The ignition power transistor located in the ignition primary
circuit turns ON and OFF to control the primary current
flow to the ignition coil. This controls the ignition timing to
provide the optimum ignition timing with respect to the
engine operating conditions. The ignition timing is deter-
mined by the PCM from engine speed, intake air volume,
engine coolant temperature, and atmospheric pressure.

DIAGNOSTIC TEST MODE

• When an abnormality is detected in one of the sensors

or actuators related to emission control, the Malfunc-
tion Indicator Lamp (SERVICE ENGINE SOON or
Check Engine Lamp) illuminates to warn the driver.

• When an abnormality is detected in one of the sensors

or actuators, a diagnostic trouble code corresponding
to the abnormality is stored in the PCM.

• The RAM data inside the PCM that is related to the

sensors and actuators can be read with the scan tool.
In addition, the actuators can be controlled by scan
tool MB991958 (MUT-III Sub Assembly) under certain
circumstances.

OTHER CONTROL FUNCTIONS

• Fuel Pump Control

Turns the fuel pump relay ON so that current is sup-
plied to the fuel pump while the engine is cranking or
running.

• A/C Compressor Clutch Relay Control

Turns the compressor clutch of the A/C ON and OFF.

• Evaporative Emission Purge Control

(Refer to GROUP 17, Emission Control System

−

Evaporative Emission System

− General Description

P.17-64

• EGR Control

(Refer to GROUP 17, Emission Control System

−

Exhaust Gas Recirculation (EGR) System

− General

Description

P.17-68

Была ли эта страница вам полезна?

Да!Нет

2 посетителя считают эту страницу полезной.

Mitsubishi Montero (2004+). Manual — part 128

Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.